[Sch_toa]

Hi all,

Just joined this forum since I have a question I would like to know how others deal with.

I am working for a Dutch school and am responsible for the chemistry lab experiments. As in all school labs, we have gas fittings for supplying gas for heating purposes, secured by lift&turn knobs and central valves and switches operated by me or the teachers for additional safety.

Now that is all fine, but despite these measures, there still remains one mayor issue at our school: students sabotaging the fittings.

I regularly find not only chewing gum and paper in the nozzles of the gas fittings, but even complete lollipop sticks and ballpoint ink reservoirs jammed inside the lift&turn knobs, with the knob turned open.

I know we should discipline our kids, but it can be a hard time with 30 kids in a room, especially since the lab spaces are used as regular school classes as well... meaning I am not present when it happens.

Does anyone know a solution to prevent the nozzles from being clogged? I have looked at something as simple as a flexible rubber or plastic cap, but not yet found anything really suitable. I am slightly surprised that non of the manufacturers of the gas fittings ever seemed to have thought of supplying tightly fitting caps for nozzles. Now that is fine from the perspective of responsible 20+ years university students or professionals working in a lab, but 12-18 year kids is something completely different.

Even better, I would maybe like to see a true lock system with a quick release with key that I could use... but that maybe a bit of fantasy and overkill and a lot of work to remove, although this has to be compared with wasting time unjamming knobs and opening clogged nozzles...

Any other ideas?

[408]

Sticking s#*$ in the gas valves...that's a paddlin'
http://www.youtube.com/watch?v=hFgR0m-9FmM

[fledarmus]

You could try making your own rubber caps. Find (or turn, if you're a woodturner) a cone that matches the shape of your fitting, coat it with a mold release (like talcum powder) and dip it into some Plasti Dip http://www.plastidip.com/home_solutions/Plasti_Dip. Repeat until you've built up a sufficiently hefty layer that you can slide off your cone. Then stick that over the fitting. Your cap will take a little effort to remove, but mostly that open hole just won't be as much of a temptation. (Make a few spares for the inevitable lost ones at every lab day).

[Sch_toa]

Thanks for the suggestion about the Plasti Dip. Might be an option, but I will have to try it. Do you know how durable this stuff is? Will it last for a while with repeated removal, like good rubber or strong plastic?

Any other suggestions are welcome!